High acculturation and aggression may signal increased risk of drug use among different ethnic groups. Drug use histories were compared with the degree of acculturation in 18 African-Americans and ten Hispanics. Aggressive responding was measured using The Point Subtraction Aggression Paradigm (PSAP) developed by Cherek, D.R., 1981, Psychopharmacology, 75, 339-345. Males were more acculturated and used more drugs than females. In PSAP responding, each gender responded more aggressively towards the ethnic group in which they identified with the most. Ethnic Identification and gender were associated with increased drug use. Acculturation and drug studies must consider the importance of gender within and across ethnic sub-populations.